1920

10 January - Europe: The Leauge of Nations is formed by 31 nations. The Treay of Versailles goes into effect. The treaty's overly-harsh treatment of Germany will prove to be one of the catalysts for the rise of Nazism.

3 December - Fiume:d'Annunzio declares war on Italy, but is soon driven from Fiume when the Italian navy bombards the city.

1921

11 July - Europe: Adolf Hitler threatens to resign from the Nazi Party unless he is made the authoritarian leader of the party.
29 July - Europe: At a Nazi gathering, Hitler is introduced as "der Führer" of the Nazis, the first time that title is used to address him.